This invention relates to improvements in smoothing of bag making material in form, fill and seal machines wherein bag making film material is formed into bags filled with product after descending from a form, fill tubular nozzle toward bag sealing means.
Examples of form, fill and seal bag making and filling machines especially relevant to the present invention are disclosed in U.S. Pat. Nos. 4,355,494 and 4,829,745, which to any extent necessary are incorporated herein by reference so that the present invention may be more succinctly disclosed herein.
The problem to which the present invention is directed is elaborately described in the aforesaid U.S. Pat. No. 4,829,745, namely that wrinkles tend to form along the edge seal lines of the bags produced as a result of the operation of the form, fill and seal machines wherein the tube of bag making material is, after it descends below the discharge end of the form and fill tube, sealed thereacross by sealing form means to form one side of a bag and then filled and sealed across to form the opposite side of the bag. As disclosed in that patent, gripper means at one side of the flattened tube and a swinging arm inside the tube cooperate to maintain a flat configuration of the bag making material relative to the sealing jaw means. That arrangement, while reasonably effective, requires mechanism functioning within the filling area of the form and fill tubular nozzle, and the present invention aims to avoid that complication.